1. Field of the Invention
The present invention relates to a telescopic device of a steering column for a vehicle, more particularly to a telescopic device of a steering column for a vehicle, in which a plurality of locking blocks are installed for providing fixing force between a telescopic outer member and a telescopic inner member, wherein the fixing force of each locking block can be equally distributed.
2. Description of the Related Art
Generally, the telescopic device is used for adjusting the length of a steering wheel according to the body type of a driver.
Referring to FIGS. 1 and 2, a typical telescopic device 100 includes a locking block 104 contacting with a telescopic inner member 112, and a tapered block 106 coupled with an operating lever 108 stacked within a block case 102 formed at the bottom side of a telescopic outer member 110.
When the tapered block 106 is moved along an inclined bottom surface of the block case 102 according to the pivot of the operating lever 108, the locking block 104 is moved vertically to selectively provide fixing force to the telescopic inner member 112 so as to make the telescopic inner member 112 closely contact and become fixed on the telescopic outer member 110 or to slide on the telescopic outer member, thereby adjusting the length of a steering shaft 114 coupled with a steering wheel (not shown) on a tip end.
The telescopic device 100 as stated above, however, is installed at a specific upper position of the steering shaft 114 adjacent to the steering wheel so as to enable a driver to easily manipulate the telescopic device, so the fixing force provided by the telescopic device 100 is hardly transmitted to the lower part of the steering shaft 114, which results in a reduction of the coupling force between the lower parts of the telescopic inner member 112 and the telescopic outer member, 110 as well as the generation of noise by the vibration due to an expanded gap.
In addition, the gap between the telescopic inner member 112 and the telescopic outer member 110 is adjusted to be reduce so as to complement the limited fixing force, but even so it results in a rise in the cost of production and the number of defective products due to the precise process of forming the mating diameter surfaces of the telescopic inner member 112 and the telescopic outer member 110, and the reliability of the product deteriorates due to the poor operation depending on the reduction of the gap.